Window shade or screen comprising two angular gearing mechanisms

ABSTRACT

A window roller blind ( 5 ) or a partition net is extended with the aid of actuating elements ( 14, 15 ), which actuating elements ( 14, 15 ) swing about an axis that extends at a right angle to the winding shaft ( 18 ) on which the respective strips of material ( 8 ) are wound up. The actuating elements ( 14, 15 ) are flexurally stiff relative to a bending plane that extends at a right angle to the planes defined by the spread-out roller blind strip ( 8 ) or the partition net.  
     There is provided for each of the actuating elements ( 14, 15 ) a angular gear ( 22, 23 ) whose output shaft carries, and rotates with, the respective actuating element ( 14, 15 ). The output shaft ( 32, 34 ) of the respective angular gear ( 22, 23 ) forms at the same time the bearing axis of the actuating element ( 14, 15 ).  
     The two angular gears ( 22, 23 ) are either driven by separate motors ( 29, 33 ), or their input shafts are mechanically coupled one with the other and are jointly driven by an electric motor ( 29 ).

[0001] A rear-window roller blind, which operates without any guides, is known from EP 0 240 747. The spring-biased winding shaft of the known rear-window roller blind is rotatably seated in a case provided on or below the rear window shelf. The blind strip is mounted on the winding shaft by one of its edges, while its other edge, parallel to the first edge, is connected with a pull rod. The pull rod simultaneously serves to stiffen the respective edge of the blind strip.

[0002] For spreading out the blind strip, and keeping it in spread-out condition, two pivot levers are seated in the winding shaft.

[0003] The free ends of the two rigid pivot levers are in sliding engagement with the pull rod. By pivoting the pivot levers in opposite directions, the blind strip is pulled off the winding shaft and is spread out against the action of the spring. At the same time, the pivot levers carry the respective edge of the blind strip in any operating condition and cooperate with the spring-biased winding shaft to keep the blind strip in spread-out condition.

[0004] Pivoting of the levers is effected via a crank gear. The levers are extended for this purpose beyond the pivoting axis. The extension serves as crank for engagement of a pull rod. The other end of each of the two pull rods is likewise connected with a crank, and these cranks rotate with the output shaft of a gear unit.

[0005] With such an arrangement, the geared motor must be arranged approximately midway between the two pivot levers. This in connection with the crank arms results in quite considerable space requirements and this, on top of everything, at an unfavorable point in the vehicle, namely in the middle of the luggage compartment, below the rear-window shelf.

[0006] Starting out from this situation, it is the object of the present invention to provide a rear-window roller blind or a partition net which has its actuating elements driven without the use of any cranks.

[0007] The invention attains this object by a device having the features defined in claim 1.

[0008] In the case of the device according to the invention, whether configured as a rear-window roller blind or as a partition net, the two actuating elements have one of their ends seated on the output shaft of a angular gear. The angular gear can have smaller dimensions than the cranks so that considerable space savings can be realized. The input shafts of the angular gears extend in parallel to the axis of the winding shaft and can be easily coupled by a shaft, including a flexible shaft.

[0009] The other possibility consists in providing each gear unit with a separate motor. Special synchronization means are not required for those motors. For pulling the blind out or drawing it in, it is sufficient if an electric current of corresponding polarity is applied to the two motors simultaneously. The normal synchronism of permanent-field d.c. motors is absolutely sufficient in the present case to prevent the blind strip from being pulled wrongly.

[0010] The use of two motors, i.e. one electric motor for each angular gear, further permits the use of motors of smaller rating and, thus, small diameter so that further considerable space savings can be achieved. In addition, it is also possible to accommodate the motor in offset arrangement.

[0011] A simple and very space-saving form of the angular gear is achieved if a worm gear is used. The worm gear provides the additional advantage that while having small overall dimensions it is capable of transmitting a relatively high torque and of strengthening the self-holding effect of the motor.

[0012] The actuating elements may consist of one-armed levers, or even toggle levers, depending on what is more convenient for the particular application.

[0013] Further developments of the invention are the subject-matter of sub-claims. It should be understood, however, that combinations for which no special embodiment is presented in the present application are likewise covered by the scope of the invention.

[0014] Certain exemplary embodiments of the invention are shown in the Figures in which:

[0015]FIG. 1 shows a perspective rear view of a motor vehicle, illustrating the rear-window roller blind according to the invention;

[0016]FIG. 2 shows a perspective view of a detail of the rear-window roller blind according to FIG. 1;

[0017]FIG. 3 shows a rear-window roller blind with a single drive motor and a coupling shaft;

[0018]FIG. 4 shows a rear-window roller blind similar to that shown in FIG. 2, using toggle levers; and

[0019]FIG. 5 shows a perspective view of a station wagon with a partition net.

[0020]FIG. 1 shows, in a very diagrammatic illustration, part of the rear end of a passenger car 1, viewed from the rear. In the perspective representation shown, there can be seen a left rear side window 2 and a rear window 3 with a mounted, usually curved windowpane 4.

[0021] Mounted in front of the inner surface of the window pane 4 is a roller blind 5, shown in its pulled-out condition in the drawing.

[0022] Further, a rear window shelf 6 can be seen in FIG. 1, which is provided with a lead-out slot 7 extending over almost the full width of the shelf. The rear window shelf 7 extends from the lower edge of the rear window 4 to the rear surface of a rear backrest not visible in detail.

[0023] As can be seen in FIG. 1, the roller blind 5 comprises a blind strip 8, consisting of a more or less transparent planar material of substantially trapezoidal cut, which is bounded by two longitudinal edges 9 and 11. Mounted on another transverse edge 12, which extends crosswise to the longitudinal edges 9 and 11, is a pull rod 13. The pull rod 13 is provided with a downwardly open guiding groove which is engaged by the free ends of two pivot levers 14 and 15 that swing in opposite directions. When the rear-window roller blind 5 is pulled out or retracted, the pivot levers 14 and 15 together with the blind strip 8 move out of the blind slot 7 or into the latter, respectively.

[0024] The structure of the rear-window roller blind 5 is shown in more detail in FIG. 2.

[0025] The rear-window roller blind 5 comprises a frame or base 16 with a full-length longitudinal groove 17 in which a winding shaft 18 is rotatably seated. The base 16 is provided for this purpose with bearing pieces 19 and 21 at the ends of the groove 17.

[0026] The blind strip 8 is mounted on the winding shaft 18 by one edge that extends in parallel to the transverse edge 12. A helical spring, not shown in detail, which is accommodated inside the tubular winding shaft 18, serves to bias the winding shaft 18 in the direction in which the blind strip 8 is wound up on the winding shaft 18.

[0027] Laterally beside the winding shaft 18, two angular gears 22 and 23 are mounted on the base 16.

[0028] The angular gear 22 comprises a gear case 24 in which a worm gear 25 is accommodated. The worm gear 25 consists of a worm wheel 26 and a worm 27. The rotary axis of the worm wheel 26, which is rotatably seated in the gear case 24, extends at a right angle to the axis of the winding shaft 18, while the worm 27 extends in parallel to the winding shaft 18.

[0029] The bearing elements or bores for the worm 27 and the worm wheel 26 are not shown in detail, since they are not essential for the understanding of the invention and since one skilled in the art knows how to seat such gear elements.

[0030] The worm 27 is mounted to rotate together with the shaft 28, which latter simultaneously represents the armature shaft of a permanent-field d.c. motor 29.

[0031] The worm wheel 26 is mounted on, and rotates with, an output shaft 32, which extends from the gear case 24 through the latter's front 31 shown in FIG. 2. The shaft carries the pivot arm 15 in flexurally stiff and non-rotating relationship, the pivot arm being provided for this purpose with a corresponding receiving bore. Consequently, the output shaft 32 of the worm wheel 26 simultaneously acts as pivoting axis for the lever 15 and extends at a right angle relative to a plane defined by the spread-out roller blind 8.

[0032] The angular gear 23 has the same design as the angular gear 22, and is likewise provided with a separate drive motor 33.

[0033] Again, the respective worm wheel axle or shaft 34 projects through the front 31 of the angular gear 23 and carries the pivot lever 14 in non-rotating relationship. The two pivot levers 14 and 15 are bent at right angles in opposite directions, as shown in the drawing, so that in the retracted condition they will occupy a parallel position below the slot 7.

[0034] As can be seen in the Figure, the two pivot levers 14 and 15 are likewise bent at right angles in opposite directions.

[0035] The pivot arms 14, 15 are flexurally stiff and are adapted to keep the roller blind 8 in spread-out condition. The necessary reaction torque must be provided by the axles 32, 34, and these, as well as their seating elements, must therefore be correspondingly robust if they are to stand the flexural torque occurring on the pivot levers 14, 15 in the extended condition, without getting damaged.

[0036] It is an advantage of this arrangement that the worm wheel 26 requires less space in the radial direction than the crank arrangement of the known rear-window roller blind. In addition, the driving power is distributed between two motors so that the diameter of each motor can be a little smaller because the motor has to provide only half of the driving power, compared with the variant employing a single motor as used in the prior art.

[0037] The two motors 29 and 33 are jointly connected to a corresponding control switch or other control means for the rear-window roller blind 5. They are switched on simultaneously and are switched off simultaneously. During the time they are running, no separate synchronization is effected between the two motors 29 and 33. The only synchronization effected consists in that the two motors 29 and 33 are mechanically blocked in their respective end positions by the fact that the pivot arm 14 or 15, respectively, runs up against a corresponding limit stop.

[0038] The operation of the illustrated roller blind 5 is as follows:

[0039] In the retracted condition, the blind strip 18 is wound up on the winding shaft under the action of a helical spring located inside the winding shaft 18. The helical spring acts as a spring motor. The pull rod 13 rests on the edges of the slot 7 and largely covers the latter in the retracted condition. The two arms 14 and 15 have been swung into a position in which they extend in parallel to the winding shaft 18.

[0040] Depending on the ratio between the distance between the two axles 32 and 34, and the length of the pivot levers 14 and 15, it may be convenient to provide in the pull rod 13 either a common guiding groove or two parallel guiding grooves. A single guiding groove can be considered if the distance between the two axles 33 and 34 is shorter than the sum of the lengths of the two pivot levers 14 and 15. On the other hand, when that sum is greater than the distance, then the pivot levers 14 and 15 would strike each other in a common groove, so that it would be convenient in. that case to provide a separate groove for each of the two levers 14 and 15.

[0041] In the retracted position, the two pivot arms 14 and 15 further abut against stationary stops that may be provided on the base 16, and this before the arms can get free of the respective guiding groove of the pull rod 13.

[0042] Another possibility of providing a mechanical stop consists in the use of an undercut groove for the levers 14 or 15 so that the pull rod 13 is pulled against the lead-out slot by the swinging force of the pivot arms 14, 15. In this case, the respective mechanical stop is formed by the mechanical contact between the pull rod and the edges of the lead-out slot 17.

[0043] If, starting out from that position, the rear-window roller blind 5 is to be extended, the current with the corresponding polarity is switched on for both motors 29 and 33 simultaneously. Given the fact that the motors run practically at the same speed, with little variance, they will set the worm wheel 26 into rotation via the worm 27 at almost identical speed so that the respective output shafts 32 and 34 will be rotated correspondingly. As the two pivot arms 14, 15 are connected to, and rotate with the respective shafts 32, 34, the pivot arms 14, 15 will be transferred from the position, in which they extend substantially in parallel to the winding shaft 18, to their upright position shown in FIG. 2. In their upright position, the two pivot levers 14, 15 extend at an approximately right angle to the winding shaft 18. On their way to that position, the two pivot levers 14 and 15 move through practically the same angular range, though in opposite directions, and reach their extended positions after almost the same time. As the motor current remains switched on for a longer period of time, it is guaranteed that each pivot arm 14, 15 actually reaches its end position defined by corresponding stops. The stops are not shown in detail in the Figure. They may be constituted by simple pins provided on the base 16.

[0044] In the case of the illustrated exemplary embodiment, the two angular gears 22 and 23 are spaced apart one from the other so that in the extended condition the pivot arms 14, 15 extend in parallel one to the other in their end position. If the fact that the pivot arms 14, 15 extend over the surface of the blind strip 8 in the extended condition is found bothersome, then the gear units 22 and 23 could be shifted outward. The pivot levers 14, 15 would then extend in parallel to the lateral edges 9 and 11 in their extended condition and would no longer appear as a nuisance.

[0045] Another quite space-saving embodiment is illustrated in FIG. 3. In the case of this embodiment, a coupling shaft 36 is used instead of the second motor 33. Any structural elements of that rear-window roller blind 5, that have been described before in connection with FIG. 2, will be designated hereafter by the same reference numerals, and their description will not be repeated here.

[0046] The coupling shaft 36 has one of its ends connected with, and rotates with, the axle stub 37 of the worm shaft 28 which projects from the gear case 24. The other end of the coupling shaft 36 is connected with, and rotates with the worm shaft of the angular gear 23.

[0047] This arrangement, too, is relatively space-saving although a single motor must provide the whole drive power. This is so because the drive motor can be shifted at one end of the base 16 so that, in the installed condition, it will come to lie in an area of the luggage compartment where it projects in downward direction into the clear profile of the luggage compartment and is less disturbing.

[0048] It is understood that in the embodiment of FIG. 3, the two angular gears 22, 23 are equiped with worms which have an opposite direction of rotation, in order to attain the contrary of the two pivot arms 14, 15 which in the exemplary embodyment of FIG. 2 is accomplished by the opposite polarity of the motors 29 and 33.

[0049]FIG. 4 shows an embodiment that differs from the exemplary embodiment according to FIG. 2 with respect to the actuating elements for the blind strip 8. To the extent any structural elements of that rear-window roller blind 5 have been described before in connection with FIG. 2, they will be designated hereafter by the same reference numerals, and will not be described again.

[0050] In the case of the exemplary embodiment illustrated in FIG. 4, a toggle lever 41, consisting of two toggle lever arms 42 and 43, is coupled with the output shaft 32. The two toggle lever arms 42 and 43 are interconnected by a toggle lever joint 44. The two toggle lever arms 42 and 43 have identical effective lengths. One end of the toggle lever arm 42 is mounted on and rotates with the output shaft 32 from which it leads to the toggle lever joint 44 whose joint axis extends in parallel to the axis 32. The second toggle lever arm 32 connects the toggle lever joint 44 with an articulation joint 45 on the pull rod 13. The axis of that joint 45 is again parallel to the axis 32.

[0051] The pivot arm 14 of the exemplary embodiment according to FIG. 2 has likewise been replaced by a toggle lever, namely toggle lever 46, Whose structure is identical to that of the toggle lever 42 and will therefore not be described once more in this context. One end of the toggle lever is connected to and rotates with the shaft 34, while its other end is pivotally connected with an articulation point 47 on the pull rod 13.

[0052] The axes of the articulation points 45, 47 and the shafts 32, 43 form the corners of a rectangle.

[0053] In operation, the two toggle levers 41 and 46 fold together, and the toggle lever joints 44 move one toward the other.

[0054] The drive for the two toggle levers 41 and 46 may be configured in the way illustrated in FIG. 2 or in FIG. 3.

[0055] The driving system of the invention, as illustrated in connection with the rear-window roller blind 5, can also be used for electrically extending and retracting partition nets 51, as illustrated by way of example in FIG. 5. The partition net 51 serves to separate a passenger compartment 52 from a cargo compartment 53 of a station wagon 1.

[0056] The partition net 51 has an oblong case 54, which is mounted on the rear surface of a backrest 55 and extends over the full vehicle width. A winding shaft similar to the winding shaft 18 of the rear-window roller blind 5 is rotatably seated inside the case 54. Mounted on that winding shaft is a knitted mesh fabric 56. The mesh fabric 56 consists of plastic threads that have been processed into a warp-knitted fabric. The mesh fabric 56 exhibits an approximately trapezoidal shape. The lateral edges are secured by bordering strips 57.

[0057] A pull rod 58, provided with hook-up means 59 on one of its ends, is mounted on the mesh structure 56 at an edge of the case 54 spaced from the winding shaft or the case 54, respectively. The hook-up means 59 are intended for being fitted in receiving pockets 51 fixed on the vehicle.

[0058] For spreading out the mesh structure 56, there are provided two levers 62, which are pivotable in opposite directions and which are connected and actuated in the same way as the pivot arms 14 and 15 of the exemplary embodiment for the rear-window roller blind 5. Accordingly, there is no need here to repeat the description of FIG. 2 or 3 as the new description would differ from the former one only in that the pivot levers would be designated by reference numeral 62 and the blind strip 8 would be formed by the mesh structure 56.

[0059] A roller blind 5 or a partition net 51 is extended with the aid of actuating elements 14, 15, 41, 46, 62, the actuating elements 14, 15, 41, 46, 62 pivoting about an axis that extends at a right angle relative to the winding shaft 18 on which the respective strips 8, 56 are wound up. The actuating elements 14, 15, 41, 46, 62 are flexurally stiff with respect to a bending plane that extends at a right angle to the planes defined by the spread-out blind strip 8, 56 or the partition net.

[0060] For each of the actuating elements 14, 15, 41, 46, 62 one angular gear 22, 23 is provided, whose output shaft carries, and rotates with, the respective actuating element 14, 15, 41, 46, 62. The output shaft 32, 34 of the respective angular gear 22, 23 forms at the same time the bearing axis for the respective actuating element 14, 15, 41, 46, 62.

[0061] The two angular gears 22, 23 are either driven by separate motors 29, 33, or else their input shafts are mechanically coupled one to the other and are jointly driven by a single electric motor 29. 

1. Window roller blind or partition net (5, 51) having a rotatably seated winding shaft (18); a strip of material (8, 56), which has one of its edges fastened on the winding shaft (18) and has its other edge stiffened by a pull rod (13, 58); two angular gears (22, 23), which are arranged in the neighborhood of the winding shaft (18) and each of which comprises an input shaft (28) and an output shaft (32, 34), the input shafts (28) extending in parallel to the winding shaft (18) and the output shafts (32, 34) extending at a right angle to the winding shaft (18), two actuating elements (14, 15, 41, 46, 62), which are connected by one end to the pull rod (13, 58), each of which is mounted on an output shaft (32, 34) in non-rotating and flexurally stiff relationship and which serve to pull the strip (8, 56) off the winding shaft (18) and to keep it in spread-out condition at least over part of the pull-out distance; and drive means (29, 33) coupled with the input shafts (28) of the gear units (22, 23).
 2. The device as defined in claim 1, characterized in that the winding shaft (18) has spring means associated with it, by which the winding shaft (18) is biased in the direction in which the strip (8, 56) is wound up.
 3. The device as defined in claim 1, characterized in that the angular gear (22, 23) is a worm gear whose worm wheel (26) is connected with, and rotates with, the output shaft (32, 33).
 4. The device as defined in claim 1, characterized in that the angular gear (22, 23) is a worm gear whose worm (27) is connected with, and rotates with, the input shaft (28).
 5. The device as defined in claim 1, characterized in that the input shaft (28) of the one angular gear (22) comprises a drive end and a driven end (37), with an electric motor (29) coupled with, and rotating with, the drive end (37), and that the other angular gear (23) comprises at least one drive end which is coupled via a shaft (36) with the driven end (37) of the input shaft (28) of the one angular gear (23).
 6. The device as defined in claim 5, characterized in that the shaft (36) is a flexible shaft.
 7. The device as defined in claim 1, characterized in that the input shaft (28) of each angular gear (22, 23) is coupled with a separate electric motor (29, 33).
 8. The device as defined in claim 1, characterized in that each of the actuating elements (14, 15, 41, 46, 62) is formed by a toggle lever (41, 46), each toggle lever (41, 46) consisting of two toggle lever arms (42, 43) that are interconnected by a toggle lever joint (44).
 9. The device as defined in claim 1, characterized in that each of the actuating elements (14, 15, 41, 46, 62) is formed by a one-armed lever. 